Résumés are NOT employment histories and yet, many individuals treat them as such including page after page after page of employment experience and including great detail about the various duties, responsibilities, and achievements at each job.
Sorry, but too much work history becomes boring.
The solution is simple: Include enough information to show any reader what you did as an employee, what you accomplished (increased sales by XX% or cut costs by YY%) and you will get the attention of any reader. Too much information and you will put any reader to sleep or, at best, encourage those assigned to ‘screen’ résumés to move on the next (and hopefully shorter) résumé.